This invention pertains to the control of the homogeneously dispersed neutron absorbing material within nuclear reactors, and more particularly to a process for maintaining an inventory of both highly concentrated and dilute boric acid solution for injection into a nuclear reactor.
A copending application 2797 filed Jan. 14, 1970 by William W. Brown et al describes a boron control system which is believed to repesent the latest pertinent prior art. This system utilizes a combination of sequentially operated ion exchange beds and an evaporative boric acid recovery apparatus to process the coolant from a nuclear reactor and to adjust the boron level to that required for a particular operation. As therein described, the ion exchange beds are provided for load follow operations, and the evaporative apparatus is provided for major changes in boron concentration. Inherent in the description of the invention was the belief the ion exchange beds of any practical volume could not handle major changes in boron concentration.
As is well known, an evaporative boric acid recovery system requires numerous supplemental systems to process the gases which are released from the fluid during heating. Moreover, some portion of these gases which contain fission products eventually are released to the environment.
Another copending application No. 791,893 filed Jan. 17, 1969 by Gottfried Gramer and Gunter Wittrowsky describes a system having only ion exchangers. However, this system is of impractical size for commercial operations.
Accordingly, it becomes highly desirable, especially in view of the emphasis on environmental control, to provide an ion exchange system capable of handling all changes in boron concentration required for all necessary changes in boron concentration.